1. Field of the Invention
The present invention relates to a structure for disposing a fuel tank for a straddle-type vehicle such as a motorcycle.
2. Description of the Related Art
A conventional fuel tank for a motorcycle has a tank outer plate and a tank bottom plate which are seam-welded together, and a projecting fuel cock formed on the tank bottom plate. The fuel tank at the side of seam-welding portions is integrally formed with extended members projecting downward below the fuel cock. The extended members are provided with mounting portions of a front cowling and a side cover.
When the fuel tank is removed from the body and placed on the ground or the like without using any jigs or the like, the extended members of the seam-welding portions function as the legs of the fuel tank so that the fuel cock can be protected. In addition, the extended members can also be used for mounting and supporting the front cowling and the side cover.
Another conventional fuel tank is mounted on a motorcycle having a pair of main frames which extend to the rear of the body from a head pipe. The fuel tank has a configuration such that it is at least partially interposed between the pair of main frames and divided into an upper and a lower part, and the mating faces of the upper and the lower parts are positioned in the vicinity of the upper edges of the main frames. Further, a protection member is fitted on the mating faces.
However, in the former conventional fuel tank, the seam-welding portions of the tank outer plate and the tank bottom plate hang there and are integrally formed with the extended members projecting downward below the fuel cock. The extended members are formed with the mounting portions of the front cowling and the side cover. Thus, it is difficult to form the seam-welding portions on the tank outer plate and the tank bottom plate, respectively, with good accuracy by press forming. Also, when the tank bottom plate and the tank outer plate are seam-welded together with the seam-welding portions aligned with each other, the tank bottom plate must be fitted in the tank outer plate in position. However, when the tank outer plate and the tank bottom plate are not formed with a high degree accuracy, an optimum fit cannot be provided, or even when both plates are successfully fitted together, a gap may occur between the seam-welding portions resulting in a problem of difficulty in forming.
Further, in the latter conventional fuel tank, the protection member is fitted on the mating faces projecting from the side of the fuel tank which is divided into an upper and a lower part. The protection member prevents the fuel tank from being in surface contact with the main frame so that no vibration is directly transmitted from the body to the fuel tank. The protection member also prevents the flanges of the fuel tank from directly interfering with rider's legs when he/she rides on the vehicle. The protection member, however, only provides such functions, and attaching the protection member does not necessarily provide a good appearance.
In view of the foregoing, it is, therefore, an advantage of the present invention to provide a fuel tank capable of being easily formed and to provide a structure for disposing a fuel tank for a straddle-type vehicle capable of improving quality in appearance of a portion where the fuel tank is disposed.